For follow-up discussion and general commentary on the topic. Comments are sorted chronologically.
Lusanda Cele
What I have gotten from scripture is that both Cain and Abel's occupations, for a lack of a better word, were indicative as well as symbolic of the type of lifestyles they lead. Abel was a sheep keeper; we have seen scripture in the New Testament where Jesus instructed people to tend to His sheep if they loved him, amd that is what Abel did, while Cain was a worker of the ground which was cursed by God in Genesis 3:17. This suggests that he was in complete rebellion of what God would have had him in do in the first place, he was a worker of evil, if put in simple terms. This I've also concluded because of God's words in 4:10 " The voice of your brother is crying to me from the ground." The very same ground Cain 'worked'
Cain simply offered God something evil and cursed, and was unacceptable.
Greeshma Nemalikanti
In Genesis 4:4, 5 (NLT version) ” The LORD accepted Abel and his gift, but he did not accept Cain and his gift.
The bible verses tell us that Lord first accepted Abel and then his offering. He humbled himself before the Lord and with fullness of spirit he gave sacrifices to Lord.
But in Cain's case, his body was present to give offering but he didn't do with his mind and soul, and so God neither accepted Cain nor his offering.
It is like praising God with mouth but not with heart.
James Kraft
Romans 11:6. Romans 4:5 Salvation by works never works. Matthew 7:21-23. Mans works can not save sinners. Man cannot save himself.
Abel gave a blood sacrifice for his sin. Cain tried to be saved by works. The works of his own hands.
Roman 4:1-8. For if Abraham were justified by works, he would have something to glory in, but not before God. Abraham was justified by faith apart from works before God. He was justified before men by good works.
Romans 4:5 But to him that worketh not, but believeth on Him who justifieth the ungodly, his faith is counted for righteousness.
We have to be as righteous as God to go to heaven, and no one is. But He has imputed His righteousness to our account apart from works. Our works have no value to God. Only the one blood sacrifice of His Son that covers us from all sin past, present, and future sins we have not even thought of yet.
Romans 4:7-8. First John 2:2. For He is the propitiation for our sins, and not for ours only, but for the sins of the whole world.